The present invention relates to apparatus for providing hot water for divers' suits. Pumping hot water to divers' suits is conventional but heretofore the equipment for such heating apparatus was cumbersome, required permanent installations or required complicated and extensive back-up systems such as ships or barges and was not easily portable, often requiring additional engines or additional electric or steam supply which were difficult to move from one installation to another. See for example U.S. Pat. No. 4,208,152 issued June 17, 1980 and the references cited therein.